Fluid collection gutter for a geared turbine engine

ABSTRACT

A turbine engine system includes a gutter and a gear train with an axial centerline. The gutter is disposed radially outside of the axial centerline. The gutter includes an inner surface and a channel that receives fluid directed out of the gear train. The inner surface at least partially defines a bore in which the gear train is arranged. The channel extends radially into the gutter from the inner surface, and circumferentially to a channel outlet. The bore has a cross-sectional bore area, and the channel has a cross-sectional channel area that is substantially equal to or less than about two percent of the bore area.

This application claims priority to PCT Patent Application No.PCT/US13/21575 filed Jan. 15, 2013, which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Technical Field

This disclosure relates generally to a turbine engine and, moreparticularly, to a fluid collection gutter for a turbine engine geartrain.

2. Background Information

A typical geared turbofan engine includes a fan section, a compressorsection, a combustor section and a turbine section. A rotor of the fansection is connected to and driven by a rotor of the turbine sectionthrough a shaft and a gear train. During engine operation, lubricationoil is provided to the gear train to lubricate and cool components ofthe gear train. The gear train may subsequently direct this lubricationoil to a gutter that circumscribes the gear train.

Various gutter configurations are known in the art, some of which mayhave relatively low oil capture efficiencies. Such a gutter thereforemay collect a relatively small amount of the lubrication oil that isinitially directed to the gutter by the gear train. The uncollectedlubrication oil may churn in a space defined radially between the gutterand the gear train. The churning lubrication oil may re-contact the geartrain, which may reduce power transfer efficiency of the gear trainbetween the turbine rotor and the fan rotor. A low oil captureefficiency may also reduce the amount of lubrication oil available to anauxiliary lubrication system, which provides the lubrication oil to thegear train during negative g maneuvers.

There is a need in the art for a gutter with an improved fluid captureefficiency.

SUMMARY OF THE DISCLOSURE

According to an aspect of the invention, a turbine engine system isprovided that includes a gutter and a gear train with an axialcenterline. The gutter is disposed radially outside of the axialcenterline. The gutter includes an inner surface and a channel thatreceives fluid directed out of the gear train. The inner surface atleast partially defines an axial bore in which the gear train isarranged. The channel extends radially into the gutter from the innersurface, and circumferentially to a channel outlet. The bore has across-sectional bore area, and the channel has a cross-sectional channelarea that is substantially equal to or less than about two percent ofthe bore area.

According to another aspect of the invention, another turbine enginesystem is provided that includes a gutter and a gear train with an axialcenterline. The gutter is disposed radially outside of the axialcenterline. The gutter at least partially circumscribes the gear train,and includes an inner surface and a channel that receives fluid directedout of the gear train. The channel extends radially into the gutter fromthe inner surface, and circumferentially to a channel outlet. The innersurface has a surface radius. The channel has a radially extendingchannel height that is substantially equal to or less than about eightpercent of the surface radius.

According to still another aspect of the invention, another turbineengine system is provided that includes a gutter and a gear train withan axial centerline. The gutter is disposed radially outside of theaxial centerline. The gutter at least partially circumscribes the geartrain, and includes an inner surface and a channel that receives fluiddirected out of the gear train. The channel extends radially into thegutter from the inner surface, and circumferentially to a channeloutlet. The inner surface has a surface radius. The channel has anaxially extending channel width that is substantially equal to or lessthan about fifteen percent of the surface radius.

The inner surface may at least partially define a bore in which the geartrain is arranged. The bore may have a cross-sectional bore area, andthe channel may have a cross-sectional channel area that may besubstantially equal to or less than about two percent of the bore area.

The channel may have an axially extending channel width that may besubstantially equal to or less than about fifteen percent of the surfaceradius. The channel may also or alternatively have a radially extendingchannel height that may be substantially equal to or less than abouteight percent of the surface radius.

The inner surface may have a surface radius. The channel may have aradially extending channel height that may be substantially equal to orless than about eight percent of the surface radius. The channel mayalso or alternatively have an axially extending channel width that maybe substantially equal to or less than about fifteen percent of thesurface radius.

The channel area may be defined by at least a portion of the channellocated adjacent and upstream of the channel outlet.

The channel outlet may have a cross-sectional outlet area that may bebetween about fifty-five and about seventy-five percent of the channelarea.

At least a portion of the channel may have a cross-sectional geometrythat may transition between a first geometry and a second geometry asthe channel extends circumferentially within the gutter.

At least a portion of the channel may have a substantially rectangularcross-sectional channel geometry.

The channel may extend radially into the gutter to a channel end. Atleast a portion of the channel may have a cross-sectional channelgeometry that may taper axially as the channel extends radially towardsthe channel end.

At least a portion of the channel may have a cross-sectional channelgeometry formed by an inner region and an outer region located radiallyoutboard of the inner region. The inner region may have a substantiallyrectangular geometry, and the outer region may have a substantiallytriangular geometry.

The channel outlet may have a substantially triangular cross-sectionalgeometry.

The gutter may include a conduit that extends through the gutter and/orspirals at least partially around the centerline between the channeloutlet and a conduit outlet.

The gear train may include one or more fluid passages arrangedcircumferentially around the centerline and aligned axially with thechannel. The one or more fluid passages may be fluidly coupled to thechannel outlet through the channel.

The gear train may be configured as a planetary gear train or a stargear train, or any other type of epicyclic gear train.

The system may include a plurality of turbine engine rotors arrangedalong the axial centerline. The engine rotors may include a first rotorand a second rotor. Each of the engine rotors may include a plurality ofrotor blades arranged around and connected to a rotor disk. The firstrotor may be connected to and driven by the second rotor through thegear train.

The first rotor may be configured as a fan rotor and/or the second rotormay be configured as a turbine rotor. Alternatively, the first and/orthe second rotors may be configured as any other type of turbine enginerotor.

The foregoing features and the operation of the invention will becomemore apparent in light of the following description and the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial side sectional illustration of a turbine enginesystem;

FIG. 2 is an illustration of an end of a star gear train for the systemof FIG. 1;

FIG. 3 is a schematic side section illustration of a planetary geartrain for the system of FIG. 1;

FIG. 4 is an illustration of an end of a gutter for the system of FIG.1;

FIG. 5 is a partial sectional illustration of a gutter for the system ofFIG. 1 at a first circumferential position about an axial centerline;

FIG. 6 is a partial sectional illustration of the gutter of FIG. 5 at asecond circumferential position about the axial centerline;

FIG. 7 is a partial sectional illustration of another gutter for thesystem of FIG. 1 at a first circumferential position about an axialcenterline;

FIG. 8 is a partial sectional illustration of the gutter of FIG. 7 at asecond circumferential position about the axial centerline;

FIG. 9 is a partial sectional illustration of the gutter of FIG. 7during system operation;

FIG. 10 is a partial sectional illustration of another gutter duringsystem operation;

FIG. 11 is a partial sectional illustration of another gutter for thesystem of FIG. 1 at a first circumferential position about an axialcenterline;

FIG. 12 is a partial sectional illustration of the gutter of FIG. 11 ata second circumferential position about the axial centerline;

FIG. 13 is a partial sectional illustration of another gutter for thesystem of FIG. 1 at a first circumferential position about an axialcenterline;

FIG. 14 is a partial sectional illustration of the gutter of FIG. 13 ata second circumferential position about the axial centerline; and

FIG. 15 is a side cutaway illustration of a geared turbine engine.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a turbine engine system 20 that includes a gear train22 (e.g., an epicyclic gear train), a rotational input element 24 and arotational output element 26. The gear train 22 has an axial centerline28, and is connected to and transmits mechanical power between the inputelement 24 and the output element 26. The input element 24 is a turbineengine shaft, and the output element 26 is a turbine engine rotor (e.g.,a fan rotor).

Referring to FIGS. 1 and 2, the gear train 22 includes a plurality ofgears 30, 31 a-e and 32 arranged in a star gear train configuration.Alternatively, the gears may be arranged in a planetary gear trainconfiguration, or any other type of gear train configuration. Forexample, FIG. 3 is a schematic illustration of another gear train 22′that includes a plurality of gears 30′, 31 a-b′ and 32′ arranged in aplanetary gear train configuration. Referring again to FIGS. 1 and 2,the gears include a sun gear 30, one or more star gears 31 a-e, and aring gear 32.

The sun gear 30 is rotatable about the centerline 28, and is connectedto the input shaft 24 through a joint such as a spline joint. The stargears 31 a-e are arranged circumferentially around the centerline 28.The star gears 31 a-e are radially meshed between the sun gear 30 andthe ring gear 32. Each of the star gears 31 a-e is rotatable about arespective axis 34 a-e.

Each of the star gears 31 a-e is rotatably connected to a stationarygear carrier 36 through a respective bearing 38 a-e. Each bearing 38 a-emay be a journal bearing as illustrated in FIGS. 1 and 2, oralternatively any other type of bearing such as a roller elementbearing, etc. The gear carrier 36 is connected to a turbine engine casethrough a support strut and/or a flexible support.

The ring gear 32 is rotatable about the centerline 28, and is connectedto the output element 26 through a joint such as a bolted flange joint.Alternatively, the ring gear may be connected to the input element andthe sun gear may be connected to the output element.

The turbine engine system 20 also includes a fluid collection gutter 40that at least partially circumscribes the gear train 22. The gutter 40of FIG. 2, for example, is configured as an annular body that extendscircumferentially around the centerline 28. The gutter 40 includes agutter inner surface 42, a fluid collection channel 44 and a fluidreturn conduit 46. The inner surface 42 at least partially defines abore 48 (e.g., an axial gutter bore) in which the gear train 22 isarranged.

Referring to FIG. 4, the bore 48 has an inner surface 42 that is definedby a substantially circular cross-sectional geometry. The inner surface42 has a bore area defined by a surface radius 50. Alternatively, thebore 48 may have various other non-circular (e.g., arcuate or polygonal)cross-sectional geometries that define the bore area.

Referring to FIGS. 5 and 6, the channel 44 is defined by one or moresurfaces of the gutter 40, which may include a channel end surface 52and opposing channel side surfaces 54 and 56. That is, geometrically,the channel 44 extends radially outward into the gutter 40 from theinner surface 42 to the end surface 52. Axially, the channel 44 extendswithin the gutter 40 between the side surfaces 54 and 56.Circumferentially, the channel 44 extends through the gutter 40 to achannel outlet 58, which is also an inlet (e.g., scoop) for the conduit46.

The channel 44 has a substantially rectangular cross-sectional geometrywith a cross-sectional channel area. Various other cross-sectionalgeometries may define the channel, as described below.

Referring to FIGS. 4 to 6, at least a portion of the area of the channel44, located proximate (e.g., adjacent) and upstream of the channeloutlet 58, is substantially equal to or less than between about twopercent of the bore area. The channel height 60, in the engine radialdirection, extends from the gutter inner surface 42 to the gutter endsurface 52, and is substantially equal to or less than between abouteight percent of the surface radius 50. The channel width 62, in theengine axial direction, extends between the gutter side surfaces 54 and56, and is substantially equal to or less than between about five andabout fifteen percent of the surface radius 50. These dimensionalrelationships may increase a fluid capture efficiency of the gutter 40as described below.

Referring to FIG. 6, the channel outlet 58 has a substantiallyrectangular cross-sectional geometry. Alternatively, the channel outletmay have various other cross-sectional geometries that define the outletarea as described below. Referring to FIGS. 5 and 6, the rectangularcross-sectional geometry defines a cross-sectional outlet area that issubstantially equal to between about fifty-five and about seventy-fivepercent of the channel area. This dimensional relationship may furtherincrease the fluid capture efficiency of the gutter 40 as describedbelow.

The conduit 46 is defined by one or more interior surfaces of the gutter40, which may include opposing conduit end surfaces 64 a-b and opposingconduit side surfaces 66 a-b. In the engine radial direction, theconduit 46 extends within the gutter 40 between the end surfaces 64 a-b.In the engine axial direction, the conduit 46 extends within the gutter40 between the side surfaces 66 a-b. The conduit 46 extends through thegutter 40 and may at least partially spiral around the centerline 28from the channel outlet 58 to a conduit outlet 68 (see FIG. 2).

Referring to FIGS. 1, 2, 5 and 6, the gutter 40 is connected to astationary support 70 such as a support strut that connects a bearing 72to the turbine engine case. The gear train 22 is arranged and mated withthe gutter 40. The channel 44 is aligned in the engine axial directionwith one or more fluid passages 74 included in the gear train 22. Thesefluid passages 74 are arranged circumferentially around the centerline28, and extend in the engine radial direction through the ring gear 32.The channel 44 is arranged in the engine axial direction between a pairof annular seals 76 (e.g., knife edge seals), which engage (e.g.,contact) the gutter inner surface 42 in the engine radial direction. Inthis manner, the fluid passages 74 are fluidly coupled to the channel 44and thus to the conduit 46 through the channel 44.

During system 20 operation, an inlet manifold 78 provides lubricationand/or heat exchange fluid (e.g., lubrication oil) to the gear train 22.The fluid may lubricate meshing surfaces of the sun, star and ring gears30, 31 a-e and 32 and/or engaging surfaces of the star gears 31 a-e andthe bearings 38 a-e. The fluid may also or alternatively remove heatenergy from the sun, star and ring gears 30-32 and/or the bearings 38a-e.

The fluid is collected from the gear train 22 with the gutter 40.Centrifugal force induced by rotation of the ring gear 32, for example,may cause at least a portion of the fluid within the gear train 22 toflow through the fluid passages 74 and radially into the channel 44. Thechannel outlet 58 directs (e.g., scoops) the fluid from the channel 44into the conduit 46. The conduit 46 directs the fluid to the conduitoutlet 68, which may be fluidly coupled to a fluid reservoir (e.g., anauxiliary oil reservoir for the gear train 22) or to any otherlubrication system component. The fluid may subsequently be cooledand/or filtered, and re-circulated through the gear train 22 for furthergear train component lubrication and/or cooling.

Under certain conditions, gas (e.g., air) within a plenum 80 surroundingthe gear train 22 may flow with the fluid through the fluid passages 74into the channel 44. The gas may also or alternatively leak into thechannel 44 from between the gutter 40 and one or more of the seals 76.The ratio of gas to fluid within the channel 44 may affect the captureefficiency of the gutter 40. The term “capture efficiency” may describethe ratio of an amount of fluid output by the channel outlet 58 to anamount of fluid that initially flows into the channel 44 from the geartrain 22.

Where the ratio of gas to fluid within a gutter channel is relativelylarge, the gas may reduce the velocity of the fluid in the enginecircumferential direction. Such a reduction in circumferential velocitymay cause the fluid to swirl within the channel increasing leakage atthe end surface and thus the channel outlet; e.g., churn within thechannel. The churning fluid may subsequently re-contact the ring gear,which may reduce power transfer efficiency of the gear train between theinlet and the outlet elements. The disclosed gutter 40, however, mayreduce the ratio of gas to fluid within the channel 44 and thus increasethe capture efficiency of the gutter 40 where the channel area is sizedsubstantially equal to or less than about two percent of the bore areaas set forth above. Such a configuration, for example, balances thechannel area to fluid velocity relationship. Where the channel isrelatively large, for example, the fluid velocity slows and may beunable to pressurize the auxiliary tanks. Where the channel isrelatively small, the side leakage increases causing low captureefficiency.

The ratio of the outlet area to the channel area may also affect thecapture efficiency of the gutter 40. For example, where the ratio of theoutlet area to the channel area is relatively large, a relatively largechannel outlet may receive (e.g., scoop) a relatively large amount ofthe gas from the channel along with the fluid. This received gas maychoke or otherwise obstruct the flow of the fluid through the conduit,which may reduce the amount of the fluid the gutter collects and thusthe capture efficiency of the gutter. Alternatively, where the ratio ofthe outlet area to the channel area is relatively small, a relativelysmall size of the channel outlet may restrict the amount of fluid thatis received from the channel and thus reduce the capture efficiency ofthe gutter. The disclosed gutter 40, however, may reduce air chokingwithin the conduit 46 without restricting the amount of gas receivedfrom the channel 44 where the outlet area is substantially equal tobetween about fifty-five and about seventy-five percent of the channelarea as set forth above.

FIG. 7 illustrates the gutter 40 with an alternative embodiment channel82. In contrast to the channel 44 of FIG. 5, at least a portion of thechannel 82 has a cross-sectional tapered channel geometry (e.g., amulti-region channel geometry) that defines the channel area. Referringto FIG. 8, as the channel 82 extends around the centerline 28, thetapered channel geometry transitions into a different (e.g.,substantially rectangular) cross-sectional channel geometry.Alternatively, the entire channel 82 may have the tapered channelgeometry.

Referring again to FIG. 7, the tapered channel geometry axially tapersas the channel 82 extends radially into the gutter 40 towards a channelend 84. The tapered channel geometry is formed by an inner region 86 andan outer region 88, each having a unique (e.g., different) geometry. Theinner region 86 extends radially into the gutter 40 from the innersurface 42, and has a substantially rectangular geometry. The outerregion 88 is located radially outboard of the inner region 86. The outerregion 88 extends radially into the gutter 40 from the inner region 86to the channel end 84, and has a substantially triangular geometry.Referring to FIG. 8, the channel outlet 58′ has a correspondingsubstantially triangular cross-sectional geometry that defines theoutlet area.

Referring to FIGS. 8 and 9, the tapered channel geometry may increasethe capture efficiency of the gutter 40 by directing the received fluidradially outward towards the channel end 84. Canted surfaces 90 thatdefine the outer region 88, for example, may funnel the fluid towardsthe channel end 84, and reduce swirl within the channel. The fluid maytherefore collect into a mass at (e.g., proximate, adjacent or on) thechannel end 84 as the fluid flows through the channel 82 towards thechannel outlet 58′. Such a fluid mass may also be less affected byswirling gas within the channel 82 than dispersed fluid droplets. Incontrast, as illustrated in FIG. 10, swirling gas within a channel 92with a rectangular cross-sectional geometry may cause some of the fluidto swirl out of the channel 92 and thus away from the channel outlet.The rectangular cross-sectional geometry therefore may decrease thecapture efficiency of the gutter 94.

FIG. 11 illustrates the gutter 40 with another alternative embodimentchannel 96. In contrast to the channel 82 of FIG. 7, the tapered channelgeometry is formed by an inner region 98 and an outer region 100, eachhaving a unique (e.g., different) width in the engine axial direction.Each also has a substantially uniform geometry.

The inner region 98 extends in the engine radial direction into thegutter 40 from the inner surface 42. The inner region 98 has asubstantially rectangular geometry with a first width 102. The outerregion 100 is located outboard in the engine radial direction of theinner region 98. The outer region 100 extends in the engine radialdirection into the gutter 40 from the inner region 98 to the channel end84. The outer region 100 has a substantially rectangular geometry with asecond width 104 that is less than the first width 102.

Referring to FIG. 12, the channel outlet 58″ has a correspondingsubstantially rectangular cross-sectional geometry. This geometrydefines the outlet area.

FIG. 13 illustrates the gutter 40 with still another alternativeembodiment channel 106. In contrast to the channel 82 of FIG. 7, thetapered channel geometry is formed by an inner region 108, anintermediate region 110 and an outer region 112, each having a uniquegeometry and/or a unique width in the engine axial direction. The innerregion 108 extends into the gutter 40 in the engine radial directionfrom the inner surface 42. The inner region 108 has a substantiallyrectangular geometry with a first width 114. The intermediate region 110is located outboard in the engine radial direction of the inner region108. The region 110 extends into the gutter 40 in the engine radialdirection from the inner region 108.

The intermediate region 110 has a substantially trapezoidal geometry.The outer region 112 is located outboard of the inner in the engineradial direction and the intermediate regions 108 and 110. The region110 extends into the gutter 40 in the engine radial direction from theintermediate region 110 to the channel end 84.

The outer region 112 has a substantially rectangular geometry with asecond width 116 that is less than the first width 114. Referring toFIG. 14, the channel outlet 58′″ has a tapered (e.g., multi-region)cross-sectional geometry that corresponds to the geometries of theintermediate and the outer regions 110 and 112.

The gutter 40 may have various configurations other than those describedabove and illustrated in the drawings. For example, the gutter 40 mayhave a tapered cross-sectional geometry where the channel area isgreater than about two percent of the bore area. In addition oralternatively, the gutter 40 may have a channel height that is greaterthan about eight percent of the surface radius, and/or a channel widththat is greater than about fifteen percent of the surface radius. Inaddition or alternatively, the gutter 40 may have an outlet area that isless than about fifty-five percent of the channel area, or that isgreater than about seventy-five percent of the channel area. The taperedcross-sectional geometry may have a single channel region with asubstantially triangular or trapezoidal geometry, or any other type ofaxially tapered geometry. The gutter 40 may include a fluid baffle 118(e.g., an apertured oil baffle) as illustrated in FIG. 1, or may beconfigured without a baffle as illustrated in FIG. 10. The gutter 40 maybe configured as a stator as described above, or alternativelyconfigured to rotate about the centerline 28; e.g., with the ring gear32. The present invention therefore is not limited to any particulargutter configurations.

FIG. 15 is a side cutaway illustration of a geared turbine engine 220which may include the turbine engine system 20 of FIG. 1. The turbineengine 220 is a two-spool turbofan that generally incorporates a fansection 222, a compressor section 224, a combustor section 226 and aturbine section 228. Alternative engines might include an augmentorsection (not shown) among other systems or features. The fan section 222drives air along a bypass flowpath while the compressor section 224drives air along a core flowpath for compression and communication intothe combustor section 226 then expansion through the turbine section228. Although depicted as a turbofan gas turbine engine in the disclosednon-limiting embodiment, it should be understood that the conceptsdescribed herein are not limited to use with turbofans as the teachingsmay be applied to other types of turbine engines such as a three-spool(plus fan) engine wherein an intermediate spool includes an intermediatepressure compressor (IPC) between the LPC and HPC and an intermediatepressure turbine (IPT) between the HPT and LPT.

The engine 220 generally includes a low spool 230 and a high spool 232mounted for rotation about an engine central longitudinal axis Arelative to an engine static structure 236 via several bearingstructures 238. The low spool 230 generally includes an inner shaft 24that interconnects a fan 242, a low pressure compressor 244 (“LPC”) anda low pressure turbine 246 (“LPT”). The inner shaft 24 drives a fanrotor 26 of the fan 242 directly or through a geared architecture 248 todrive the fan 242 at a lower speed than the low spool 230. An exemplaryreduction transmission is an epicyclic transmission, namely a planetaryor star gear system.

The high spool 232 includes an outer shaft 250 that interconnects a highpressure compressor 252 (“HPC”) and high pressure turbine 254 (“HPT”). Acombustor 256 is arranged between the high pressure compressor 252 andthe high pressure turbine 254. The inner shaft 24 and the outer shaft250 are concentric and rotate about the engine central longitudinal axisA (e.g., the centerline 28) which is collinear with their longitudinalaxes.

Core airflow is compressed by the low pressure compressor 244 then thehigh pressure compressor 252, mixed with the fuel and burned in thecombustor 256, then expanded over the high pressure turbine 254 and lowpressure turbine 246. The turbines 254, 246 rotationally drive therespective low spool 230 and high spool 232 in response to theexpansion.

The main engine shafts 24, 250 are supported at a plurality of points bybearing structures 238 within the static structure 236. It should beunderstood that various bearing structures 238 at various locations mayalternatively or additionally be provided.

In one non-limiting example, the gas turbine engine 220 is a high-bypassgeared aircraft engine. In a further example, the gas turbine engine 220bypass ratio is greater than about six (6:1). The geared architecture248 can include an epicyclic gear train (e.g., the gear train 22), suchas a planetary gear system or other gear system. An example epicyclicgear train has a gear reduction ratio of greater than about 2.3:1, andin another example is greater than about 2.5:1. The geared turbofanenables operation of the low spool 230 at higher speeds which canincrease the operational efficiency of the low pressure compressor 244and low pressure turbine 246 and render increased pressure in a fewernumber of stages.

A pressure ratio associated with the low pressure turbine 246 ispressure measured prior to the inlet of the low pressure turbine 246 asrelated to the pressure at the outlet of the low pressure turbine 246prior to an exhaust nozzle of the gas turbine engine 220. In onenon-limiting embodiment, the bypass ratio of the gas turbine engine 220is greater than about ten (10:1), the fan diameter is significantlylarger than that of the low pressure compressor 244, and the lowpressure turbine 246 has a pressure ratio that is greater than about 5(5:1). It should be understood, however, that the above parameters areonly exemplary of one embodiment of a geared architecture engine andthat the present disclosure is applicable to other gas turbine enginesincluding direct drive turbofans.

In one embodiment, a significant amount of thrust is provided by thebypass flow path B due to the high bypass ratio. The fan section 222 ofthe gas turbine engine 220 is designed for a particular flightcondition—typically cruise at about 0.8 Mach and about 35,000 feet. Thisflight condition, with the gas turbine engine 220 at its best fuelconsumption, is also known as bucket cruise Thrust Specific FuelConsumption (TSFC). TSFC is an industry standard parameter of fuelconsumption per unit of thrust.

Fan Pressure Ratio is the pressure ratio across a blade of the fansection 222 without the use of a Fan Exit Guide Vane system. The low FanPressure Ratio according to one non-limiting embodiment of the examplegas turbine engine 220 is less than 1.45. Low Corrected Fan Tip Speed isthe actual fan tip speed divided by an industry standard temperaturecorrection of “T”/518.7^(0.5) in which “T” represents the ambienttemperature in degrees Rankine. The Low Corrected Fan Tip Speedaccording to one non-limiting embodiment of the example gas turbineengine 220 is less than about 1150 fps (351 m/s).

A person of skill in the art will recognize the turbine engine system 20of FIG. 1 may be included in various turbine engines other than the onedescribed above. The turbine engine system 20, for example, may beincluded in a geared turbine engine where a gear train connects one ormore shafts to one or more rotors in a fan section and/or a compressorsection. Alternatively, the turbine engine system 20 may be included ina turbine engine configured without a gear train. The present inventiontherefore is not limited to any particular types or configurations ofturbine engines.

The terms “upstream”, “downstream”, “inner” and “outer” are used toorient the components of the turbine engine system 20 described aboverelative to the turbine engine and its axis. A person of skill in theart will recognize, however, one or more of these components may beutilized in other orientations than those described above. The presentinvention therefore is not limited to any particular spatialorientations.

While various embodiments of the present invention have been disclosed,it will be apparent to those of ordinary skill in the art that many moreembodiments and implementations are possible within the scope of theinvention. For example, the present invention as described hereinincludes several aspects and embodiments that include particularfeatures. Although these features may be described individually, it iswithin the scope of the present invention that some or all of thesefeatures may be combined within any one of the aspects and remain withinthe scope of the invention. Accordingly, the present invention is not tobe restricted except in light of the attached claims and theirequivalents.

What is claimed is:
 1. A turbine engine system, comprising: a gear trainwith an axial centerline; and a gutter disposed radially outside of theaxial centerline, the gutter including an inner surface at leastpartially defining an axial bore in which the gear train is arranged;and a channel that receives fluid directed out of the gear train, thechannel extending radially into the gutter from the inner surface, andcircumferentially to a channel outlet; wherein the axial bore has across-sectional bore area, and the channel has a cross-sectional channelarea that is equal to or less than two percent of the cross-sectionalbore area.
 2. The turbine engine system of claim 1, wherein thecross-sectional channel area is defined by at least a portion of thechannel located adjacent and upstream of the channel outlet.
 3. Theturbine engine system of claim 1, wherein the inner surface has asurface radius; and the channel has a radially extending channel heightthat is equal to or less than eight percent of the surface radius. 4.The turbine engine system of claim 1, wherein the inner surface has asurface radius; and the channel has an axially extending channel widththat is equal to or less than fifteen percent of the surface radius. 5.The turbine engine system of claim 1, wherein the channel outlet has across-sectional outlet area that is between fifty-five and seventy-fivepercent of the cross-sectional channel area.
 6. The turbine enginesystem of claim 1, wherein at least a portion of the channel has across-sectional channel geometry that transitions between a firstgeometry and a second geometry as the channel extends circumferentiallywithin the gutter.
 7. The turbine engine system of claim 1, wherein atleast a portion of the channel has rectangular cross-sectional channelgeometry.
 8. The turbine engine system of claim 1, wherein the channelextends radially into the gutter to a channel end; and at least aportion of the channel has a cross-sectional channel geometry thattapers axially as the channel extends radially towards the channel end.9. The turbine engine system of claim 1, wherein at least a portion ofthe channel has a cross-sectional channel geometry formed by an innerregion and an outer region located radially outboard of the innerregion; and the inner region has a rectangular geometry, and the outerregion has a triangular geometry.
 10. The turbine engine system of claim1, wherein the channel outlet has a triangular cross-sectional geometry.11. The turbine engine system of claim 1, wherein the gutter furtherincludes a conduit that extends through the gutter and spirals at leastpartially around the axial centerline between the channel outlet and aconduit outlet.
 12. The turbine engine system of claim 1, wherein thegear train includes one or more fluid passages arrangedcircumferentially around the axial centerline and aligned axially withthe channel; and the one or more fluid passages are fluidly coupled tothe channel outlet through the channel.
 13. The turbine engine system ofclaim 1, wherein the gear train is configured as a planetary gear trainor a star gear train.
 14. The turbine engine system of claim 1, furthercomprising: a plurality of turbine engine rotors arranged along theaxial centerline and including a first rotor and a second rotor, each ofthe turbine engine rotors including a plurality of rotor blades arrangedaround and connected to a rotor disk; wherein the first rotor isconnected to and driven by the second rotor through the gear train. 15.The turbine engine system of claim 14, wherein the first rotor isconfigured as a fan rotor and the second rotor is configured as aturbine rotor.